﻿using System;
using Coco.Library.Globalization;
using System.Text;

namespace Coco.Library
{
    public class Lunar 
    {
        public Lunar() { }

        public Lunar(DateTime solarDate)
        {
            
        }

        public int Year { get; set; }
        public int Month { get; set; }
        public int Day { get; set; }
        public bool IsLeap { get; set; }

        public DateTime Date
        {
            get
            {
                Solar solar = LunarSolar.LunarToSolar(this);

                return new DateTime(solar.solarYear, solar.solarMonth, solar.solarDay);
            }
        }

        public DayOfWeek DayOfWeek
        {
            get
            {
                return Date.DayOfWeek;
            }
        }

        public string SolarWeekString
        {
            get
            {
                int i = (int)DayOfWeek;
                return ChineseCalenderInfoCollection.ChineseWeekName[i];
            }
        }

        public string LunarYearSexagenary
        {
            get
            {
                return ChineseCalenderInfoCollection.GetTerrestrialBranch(Date);
            }
        }

        public string LunarDayString
        {
            get
            {
                return ChineseCalenderInfoCollection.ChineseDays[Day - 1];
            }
        }

        public string LunarMonthString
        {
            get { return ChineseCalenderInfoCollection.ChineseMonths[Month - 1]; }
        }

        public string LunarYearString
        {
            get
            {
                StringBuilder sb = new StringBuilder();
                int year = this.Year;
                int d;
                do
                {
                    d = year % 10;
                    sb.Insert(0, ChineseCalenderInfoCollection.ChineseNumber[d]);
                    year = year / 10;
                } while (year > 0);

                return sb.ToString();
            }
        }

        public string LunarZodiac
        {
            get
            {
                return ChineseCalenderInfoCollection.GetAnimal(Date);
            }
        }
    }

    public class Solar 
    {
        public Solar() { }

        public Solar(DateTime date)
        {
            solarDay = date.Day;
            solarMonth = date.Month;
            solarYear = date.Year;
        }

        public int solarYear; 
        public int solarMonth; 
        public int solarDay; 
    }

    public class LunarSolar 
    { 
        /* 
         * |—-4位闰月|————-13位1为30天，0为29天| 
         * */ 
        public static int[] lunar_month_days = { 1900, 0x095c, 0x14ae, 0xaa4d, 0x1a4c, 0x1b2a, 0x8d55, 0x0ad4, 0x135a, 0x495d, 0x095c, 0xd49b, 0x149a, 0x1a4a, 0xbaa5, 0x16a8, 0x1ad4, 0x52da, 0x12b6, 0xe937, 0x092e, 0x1496, 0xb64b, 0x0d4a, 0x0da8, 0x95b5, 0x056c, 0x12ae, 0x492f, 0x092e, 0xcc96, 0x1a94, 0x1d4a, 0xada9, 0x0b5a, 0x056c, 0x726e, 0x125c, 0xf92d, 0x192a, 0x1a94, 0xdb4a, 0x16aa, 0x0ad4, 0x955b, 0x04ba, 0x125a, 0x592b, 0x152a, 0xf695, 0x0d94, 0x16aa, 0xaab5, 0x09b4, 0x14b6, 0x6a57, 0x0a56, 0x1152a, 0x1d2a, 0x0d54, 0xd5aa, 0x156a, 0x096c, 0x94ae, 0x14ae, 0x0a4c, 0x7d26, 0x1b2a, 0xeb55, 0x0ad4, 0x12da, 0xa95d, 0x095a, 0x149a, 0x9a4d, 0x1a4a, 0x11aa5, 0x16a8, 0x16d4, 0xd2da, 0x12b6, 0x0936, 0x9497, 0x1496, 0x1564b, 0x0d4a, 0x0da8, 0xd5b4, 0x156c, 0x12ae, 0xa92f, 0x092e, 0x0c96, 0x6d4a, 0x1d4a, 0x10d65, 0x0b58, 0x156c, 0xb26d, 0x125c, 0x192c, 0x9a95, 0x1a94, 0x1b4a, 0x4b55, 0x0ad4, 0xf55b, 0x04ba, 0x125a, 0xb92b, 0x152a, 0x1694, 0x96aa, 0x15aa, 0x12ab5, 0x0974, 0x14b6, 0xca57, 0x0a56, 0x1526, 0x8e95, 0x0d54, 0x15aa, 0x49b5, 0x096c, 0xd4ae, 0x149c, 0x1a4c, 0xbd26, 0x1aa6, 0x0b54, 0x6d6a, 0x12da, 0x1695d, 0x095a, 0x149a, 0xda4b, 0x1a4a, 0x1aa4, 0xbb54, 0x16b4, 0x0ada, 0x495b, 0x0936, 0xf497, 0x1496, 0x154a, 0xb6a5, 0x0da4, 0x15b4, 0x6ab6, 0x126e, 0x1092f, 0x092e, 0x0c96, 0xcd4a, 0x1d4a, 0x0d64, 0x956c, 0x155c, 0x125c, 0x792e, 0x192c, 0xfa95, 0x1a94, 0x1b4a, 0xab55, 0x0ad4, 0x14da, 0x8a5d, 0x0a5a, 0x1152b, 0x152a, 0x1694, 0xd6aa, 0x15aa, 0x0ab4, 0x94ba, 0x14b6, 0x0a56, 0x7527, 0x0d26, 0xee53, 0x0d54, 0x15aa, 0xa9b5, 0x096c, 0x14ae, 0x8a4e, 0x1a4c, 0x11d26, 0x1aa4, 0x1b54, 0xcd6a, 0x0ada, 0x095c, 0x949d, 0x149a, 0x1a2a, 0x5b25};
        
        private static int[] solar_1_1 = {1900, 0xeda53, 0xedc48, 0xede3d, 0xee050, 0xee244, 0xee439, 0xee64d, 0xee842, 0xeea36, 0xeec4a, 0xeee3e, 0xef052, 0xef246, 0xef43a, 0xef64e, 0xef843, 0xefa37, 0xefc4b, 0xefe41, 0xf0054, 0xf0248, 0xf043c, 0xf0650, 0xf0845, 0xf0a38, 0xf0c4d, 0xf0e42, 0xf1037, 0xf124a, 0xf143e, 0xf1651, 0xf1846, 0xf1a3a, 0xf1c4e, 0xf1e44, 0xf2038, 0xf224b, 0xf243f, 0xf2653, 0xf2848, 0xf2a3b, 0xf2c4f, 0xf2e45, 0xf3039, 0xf324d, 0xf3442, 0xf3636, 0xf384a, 0xf3a3d, 0xf3c51, 0xf3e46, 0xf403b, 0xf424e, 0xf4443, 0xf4638, 0xf484c, 0xf4a3f, 0xf4c52, 0xf4e48, 0xf503c, 0xf524f, 0xf5445, 0xf5639, 0xf584d, 0xf5a42, 0xf5c35, 0xf5e49, 0xf603e, 0xf6251, 0xf6446, 0xf663b, 0xf684f, 0xf6a43, 0xf6c37, 0xf6e4b, 0xf703f, 0xf7252, 0xf7447, 0xf763c, 0xf7850, 0xf7a45, 0xf7c39, 0xf7e4d, 0xf8042, 0xf8254, 0xf8449, 0xf863d, 0xf8851, 0xf8a46, 0xf8c3b, 0xf8e4f, 0xf9044, 0xf9237, 0xf944a, 0xf963f, 0xf9853, 0xf9a47, 0xf9c3c, 0xf9e50, 0xfa045, 0xfa238, 0xfa44c, 0xfa641, 0xfa836, 0xfaa49, 0xfac3d, 0xfae52, 0xfb047, 0xfb23a, 0xfb44e, 0xfb643, 0xfb837, 0xfba4a, 0xfbc3f, 0xfbe53, 0xfc048, 0xfc23c, 0xfc450, 0xfc645, 0xfc839, 0xfca4c, 0xfcc41, 0xfce36, 0xfd04a, 0xfd23d, 0xfd451, 0xfd646, 0xfd83a, 0xfda4d, 0xfdc43, 0xfde37, 0xfe04b, 0xfe23f, 0xfe453, 0xfe648, 0xfe83c, 0xfea4f, 0xfec44, 0xfee38, 0xff04c, 0xff241, 0xff436, 0xff64a, 0xff83e, 0xffa51, 0xffc46, 0xffe3a, 0x10004e, 0x100242, 0x100437, 0x10064b, 0x100841, 0x100a53, 0x100c48, 0x100e3c, 0x10104f, 0x101244, 0x101438, 0x10164c, 0x101842, 0x101a35, 0x101c49, 0x101e3d, 0x102051, 0x102245, 0x10243a, 0x10264e, 0x102843, 0x102a37, 0x102c4b, 0x102e3f, 0x103053, 0x103247, 0x10343b, 0x10364f, 0x103845, 0x103a38, 0x103c4c, 0x103e42, 0x104036, 0x104249, 0x10443d, 0x104651, 0x104846, 0x104a3a, 0x104c4e, 0x104e43, 0x105038, 0x10524a, 0x10543e, 0x105652, 0x105847, 0x105a3b, 0x105c4f, 0x105e45, 0x106039, 0x10624c, 0x106441, 0x106635, 0x106849}; 
        
        private static int[] solarMonth1 = { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; 
        
        private static int[] solarMonth2 = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

        public static int GetBitInt(int data, int length, int shift) 
        { 
            return (data & (((1 << length) - 1) << shift)) >> shift; 
        }

        //WARNING: Dates before Oct. 1582 are inaccurate 
        public static long SolarToInt(int y, int m, int d) 
        { 
            m = (m + 9) % 12; 
            y = y - m / 10; 
            return 365 * y + y / 4 - y / 100 + y / 400 + (m * 306 + 5) / 10 + (d - 1); 
        }

        public static Solar SolarFromInt(long g) 
        { 
            long y = (10000 * g + 14780) / 3652425; 
            long ddd = g - (365 * y + y / 4 - y / 100 + y / 400); 
            if (ddd < 0) 
            {
                y--;
                ddd = g - (365 * y + y / 4 - y / 100 + y / 400); 
            } 
            long mi = (100 * ddd + 52) / 3060; 
            long mm = (mi + 2) % 12 + 1; 
            y = y + (mi + 2) / 12; 
            long dd = ddd - (mi * 306 + 5) / 10 + 1; 
            Solar solar = new Solar(); 
            solar.solarYear = (int)y; 
            solar.solarMonth =(int)mm; 
            solar.solarDay = (int)dd; 
            return solar; 
        }

        private static bool IsLeapYear(int y) 
        { 
            return ((y % 4 == 0 && y % 100 != 0) || (y % 400 == 0)); 
        } 
        
        public static Solar LunarToSolar(Lunar lunar) 
        { 
            Solar solar = new Solar(); 
            int days = lunar_month_days[lunar.Year - lunar_month_days[0]]; 
            int leap = GetBitInt(days, 4, 13); 
            int offset = 0; 
            int loopend = leap; 
            if (!lunar.IsLeap) 
            { 
                if (lunar.Month <= leap || leap == 0) 
                { 
                    loopend = lunar.Month - 1; 
                } 
                else 
                { 
                    loopend = lunar.Month; 
                } 
            } 
            for (int i = 0; i < loopend; i++) 
            { 
                offset += GetBitInt(days, 1, 12 - i) == 1 ? 30 : 29; 
            } 
            offset += lunar.Day;

            int solar11 = solar_1_1[lunar.Year - solar_1_1[0]];

            int y = GetBitInt(solar11, 12, 9); 
            int m = GetBitInt(solar11, 4, 5); 
            int d = GetBitInt(solar11, 5, 0);

            return SolarFromInt(SolarToInt(y, m, d) + offset - 1); 
        }

        public static Lunar SolarToLunar(Solar solar) 
        { 
            Lunar lunar = new Lunar(); 
            int index = solar.solarYear - solar_1_1[0]; 
            int data = (solar.solarYear << 9) | (solar.solarMonth << 5) | (solar.solarDay); 
            int solar11 = 0; 
            if (solar_1_1[index] > data) 
            {
                index--;
            } 
            solar11 = solar_1_1[index]; 
            int y = GetBitInt(solar11, 12, 9); 
            int m = GetBitInt(solar11, 4, 5); 
            int d = GetBitInt(solar11, 5, 0); 
            long offset = SolarToInt(solar.solarYear,solar.solarMonth,solar.solarDay)-SolarToInt(y, m, d);

            int days = lunar_month_days[index]; 
            int leap = GetBitInt(days, 4, 13);

            int lunarY = index + solar_1_1[0]; 
            int lunarM = 1; 
            int lunarD = 1; 
            offset += 1;

            for (int i = 0; i < 13; i++) 
            { 
                int dm = GetBitInt(days, 1, 12 - i) == 1 ? 30 : 29; 
                if (offset > dm) 
                { 
                    lunarM++; 
                    offset -= dm; 
                } 
                else 
                { 
                    break; 
                } 
            } 
            lunarD = (int)(offset); 
            lunar.Year = lunarY; 
            lunar.Month = lunarM; 
            lunar.IsLeap = false; 
            if (leap != 0 && lunarM > leap) 
            { 
                lunar.Month = lunarM - 1; 
                if (lunarM == leap + 1) 
                { 
                    lunar.IsLeap = true; 
                } 
            } 
            
            lunar.Day = lunarD; 
            return lunar; 
        }

        public static Lunar SolarToLunar(DateTime solarTime)
        {
            return SolarToLunar(new Solar(solarTime));
        }
    }
}
